/**
 * ***************************************************************************** Copyright (c) 2000,
 * 2005 IBM Corporation and others. All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0 which accompanies this
 * distribution, and is available at http://www.eclipse.org/legal/epl-v10.html
 *
 * <p>Contributors: IBM Corporation - initial API and implementation
 * *****************************************************************************
 */
package org.eclipse.core.internal.dtree;

/**
 * An interface for comparing two data tree objects. Provides information on how an object has
 * changed from one tree to another.
 */
public interface IComparator {
  /**
   * Returns an integer describing the changes between two data objects in a data tree. The first
   * three bits of the returned integer are used during calculation of delta trees. The remaining
   * bits can be assigned any meaning that is useful to the client. If there is no change in the two
   * data objects, this method must return 0.
   *
   * @see NodeComparison
   */
  int compare(Object o1, Object o2);
}
